Comparing Lists

[scott stephen]

Hi would just like to ask what is the best way to compare 4
lists of names and only be left with the names that show up
in more than 1 of the lists, so for the example below i have 4
lists of names and peter only shows up in 1 so he should not
make it in to the final list, but the rest show up in more
than 1 list so will make it in.

The list of names would be stored in arrays list1$(), list2$()
list3$(), list4$(), and list5$() being the new list created by
the prossess of the 4 lists.

Example

list 1
------
scott
heather
john
trevor
gail

list 2
------
scott
heather
adam
john
trevor
gail

list 3
------
scott
heather
adam
trevor
gail

list 4
------
scott
heather
adam
peter
john
trevor
gail

list 5 (output)
------
scott
heather
adam
john
trevor
gail


guess am looking for the simplest way to do this with out
writing pages of code if thats possible.

Using PB 3.5

Thanks.


------------------
-Scott

[Marco Pontello]

If the lists aren't too long (= if memory isn't a problem), you could simply:
- add all the names from the 4 lists on a new temp list
- sort the temp list
- follow the temp list from the first element and count how many times a name is repeated; if count > 1 then add that name to the 5th list

Bye!

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[This message has been edited by Marco Pontello (edited April 26, 2004).]

[Michael Mattias]

i really should 'rename' this so it shows up with 'search' because it shows 'generic' list comparisons..

win32: find differences in win32api.inc and other text files april 21, 2000

that's pb/cc code but it should give you an idea how to do it under ms-dos.

if anyone has a good idea for a 'subject' line for above drop me a note and i'll re-post it and ask the webmaster to delete the original (as i understand it there is no maintenance allowed on the subject so you have to delete and re-enter).

mcm
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